(A844) Non-Sac Contained Matrix Is the Strongest Predictive Factor for Residual Disease in Acquired Cholesteatoma

Introduction: The objective of this study was to investigate predictive factors for residual disease in acquired cholesteatoma and determine whether the quality of the matrix, sac versus non-sac contained, impacts the outcomes.

Methods: A retrospective cohort study of pediatric and adult EAONO-JOS-staged acquired cholesteatoma operated with endoscopic and combined approaches by the senior author at an academic teaching hospital from January 2015 to November 2023. Presence of residual disease was determined through second look surgery, MRI with DWI, or a minimum of one year follow-up after canal wall down mastoidectomy. Initial occurrence of residual disease was examined relative to age, sac versus non-sac contained matrix, ossicular status and surgical approaches using Cox proportional hazard models. Kaplan-Meier curves were used to visualize time to disease stratified by predictive factors.

Results: Of 105 patients who were included, 42% had residual disease. In isolation, non-sac contained cholesteatoma (HR 3.89, 95%CI 1.53-9.89), pediatric patients (HR 1.97, 95%CI 1.01-3.85), incus erosion (HR 2.43, 95%CI 1.17-5.05), and stapes erosion (HR 2.01, 95%CI 1.02-4.00) were significantly more likely to develop residual disease. EAONO/JOS stage and surgical approach were not significantly related. In multivariable modeling, only matrix quality retained significance, with non-sac contained matrix associated with a threefold higher hazard of residual disease (HR 3.05, 95%CI 1.17-7.93).

Conclusions: When accounting for several factors inherent to the disease process as well as surgical approach, a non-sac contained cholesteatoma matrix was three times more likely to lead to residual disease in acquired cholesteatoma among all ages.